Typically, spring-and-diaphragm actuators used for fluid control valves include a bolted joint attaching a diaphragm to an actuator stem, wherein the bolted joint protrudes through the diaphragm. This joint requires a seal between the bolt and actuator stem on the one hand and the diaphragm on the other hand. To provide such a seal, an applied sealant and/or a separate O-ring is typically installed, which tends to increase assembly and component costs. In addition, care must be taken to avoid over tightening of the bolt to avoid damaging the diaphragm when the bolt is tightened to attach the diaphragm to the actuator stem.